Drinking water infested with germs and parasites or steeped in toxic chemicals is the number-one health problem in the world.
It’s so big, in fact, that the United Nations has proclaimed 2005-2015 to be the “Water for Life” decade. The UN goal is to get its member nations to honor their commitments to halving the proportion of individuals without access to safe drinking water.
But such huge development programs run by international entities such as the UN are not the only way to approach the problem, say some technologists and investors. Helping local entrepreneurs to buy and operate their own water purifiers may be the most efficient way to bring fresh water to the poor, according to famed inventor Dean Kamen and international financier Iqbal Quadir, a fellow at Harvard University’s John F. Kennedy School of Government.
Kamen, inventor of the Segway personal transporter, described his design for a simple, energy-efficient water purifier at last week’s Emerging Technology Conference, hosted by Technology Review (see last week’s story).
The concept has just gotten a boost, according to Quadir, from the successful completion of a trial in two small villages outside of Dhaka, Bangladesh, using an electrical generator designed by Kamen that could power the water purifier.
While the generator and water purifier have not been tried out in tandem in a rural setting, the tests showed that the generator can produce enough power to run the purifier. And the trial proved that the generator can even be fueled by gas produced by local cows’ dung. What’s more, it was a local entrepreneur who gathered the fuel and sold the power to local villagers.
Kamen and Quadir’s hope is that the two machines can be manufactured at a price that thousands of local entrepreneurs in developing countries could afford through small loans. In Bangladesh, a microloan program founded by Quadir and run by Dhaka-based Grameen Bank, has already helped tens of thousands of rural citizens buy cell phones, bringing telephone service to 60 million rural Bangladeshis.
Other experts consider the plan promising, but note that many cultural, as well as technological, obstacles must be overcome.
“Should it work the way they say it will work, it will be huge,” says Amy Smith, an inventor, MacArthur fellow, and MIT instructor who co-founded MIT’s International Development Initiative. “But it will not be easy.”
The basic design behind Kamen’s generator is nothing new. It uses Kamen’s version of a Stirling engine, which works as air heated in one chamber expands and moves a piston. The air cycles between hot and cool chambers, keeping the piston moving.
Any fuel source can be burned to heat the engine from the outside. In the villages outside Dakha, propane is available, but only sporadically, according to Quadir. Instead, the local entrepreneur gathered cow dung, put it in a bio-digester, and harvested the resulting gases.
Bangladesh’s national electrical grid is unreliable, and doesn’t even extend into the villages where the generator was tested. The trial showed that under these conditions, villagers were willing to pay twice the cost of grid power for juice from Kamen’s generator. Kamen believes that it may be possible to manufacture his generators, given enough orders, for $1,000, excluding marketing and distribution costs. If the generators can be made available at this price, Quadir estimates that the rates villagers could pay for power would be enough to make a loan program viable.
Kamen originally approached Quadir after learning of his programs to finance individual, usually poor, entrepreneurs. Through Quadir’s existing microloan program, called GrameenPhone, 175,000 Bangladeshi women have taken out loans of about $200 to buy cell phones and subscriptions, which they then sell time on to local villagers. Since 1976, Grameen Bank has loaned out $5 billion to the poor, in amounts as small as $25 for investments in livestock, or as large as several hundred dollars for housing space, which can also be used for small-scale manufacturing. The bank has recovered 99 percent of its loans, according to its website.
But the generator project can’t go anywhere until Kamen and Quadir find a manufacturer to produce the device. “It’s very hard to get big companies to start putting serious money toward tooling a product when they are not sure that the ultimate purchaser has the resources and wherewithal to pay for the product,” Kamen says.
The cell phone program, says Quadir, was successful in part because cheap handsets were already being produced in large quantities. Kamen hopes that the encouraging results of trial in Bangladesh may help convince companies to invest.
Large-scale programs designed to bring water to millions at a time depend on building extensive infrastructure. The advantage of Kamen’s generator and water purifier, he argues, is their flexibility. They can be carried into remote villages by just two people. And the generator can run on any local fuel available.
The design concept behind the water purifier, like the Stirling engine, is nothing new: it works by heating and distilling water. What does make it unique is its efficiency – the generator reclaims about 98% of the heat normally lost in the distillation process and reuses it to distill more water, Kamen says.
Running continuously on a few hundred watts of power, a single purifier should provide enough water for a village of 100 people, Kamen estimates. And it can purify water from any source, regardless of what contaminants it might contain. That rules out the need for quality testing or specialized treatment.
Amy Smith points out, however, that to use the water purifiers effectively, villagers will also need some education. Often, inadequate storage methods mean water is contaminated after it’s gathered, Smith says.
If the system works, and people know how to use it, Quadir believes the potential benefits can go beyond better health. A distributed water system owned by local entrepreneurs will employ more people than a centralized system, as Quadir’s experience with the cell phone program proved to him.
He likewise expects that distributed power, and water purification, will mean more jobs – and perhaps more democracy. Says Quadir, “Technology allows people to rise from below.”
Here’s how a Twitter engineer says it will break in the coming weeks
One insider says the company’s current staffing isn’t able to sustain the platform.
Technology that lets us “speak” to our dead relatives has arrived. Are we ready?
Digital clones of the people we love could forever change how we grieve.
How to befriend a crow
I watched a bunch of crows on TikTok and now I'm trying to connect with some local birds.
Starlink signals can be reverse-engineered to work like GPS—whether SpaceX likes it or not
Elon said no thanks to using his mega-constellation for navigation. Researchers went ahead anyway.
Get the latest updates from
MIT Technology Review
Discover special offers, top stories, upcoming events, and more.